Research to date shows that CBD is generally safe and has few, if any, minor side effects. However, CBD is a biologically active compound, and as such, it may also have unintended consequences when interacting with other medications.
This concern comes from how the body metabolises certain substances, with CBD and medication being among those needing to be metabolised. If you are on any medications and want to try CBD, it’s important to consult your doctor about everything you take – including any over the counter medications and vitamins, as well as prescribed medications.
How the body metabolises medications and substances
When you take a medication or substance, your body has to metabolise it in order to break it down. Whilst this is something that happens all over the body, such as in the gut, the liver plays a really big part in this process.
A family of enzymes called Cytochrome P450 (CYP450) does the important work of converting foreign substances so they can easily be eliminated from the body. Using straightforward terms, when you take medication, it is broken down by your body into its active compounds to allow them to be used. The enzymes then control these specific compounds and transform these into metabolites which can then influence different processes in your body.
How is CBD metabolised?
When you take CBD, whether as a vape, gummy or oil, it has to pass through your gut where it is then released into the bloodstream. From there, they travel through the bloodstream to the liver, where the hepatic portal absorbs it. The liver breaks the CBD down into its metabolites, before releasing them back into the bloodstream.
CBD and medication metabolism
The CYP450 family of enzymes is responsible both for medications and CBD when they enter the body, and CBD can interfere with these enzymes. When the enzymes are inhibited, it can become difficult for them to break down the medications in your system.
The reverse can happen too; many medications can inhibit the enzymes, and cause your body to struggle to break down CBD. If your body is metabolising a medication too slowly, you may have more medication in your system at one time than intended (even if you’ve stuck to your recommended dose). An increased level of medication in your system could exaggerate its effects, including unwanted and potentially harmful side effects.
Some substances can also speed up the work of the enzyme, metabolising too quickly and leaving too little of the medication in your system.
Can CBD interact with other medications?
As we’ve discovered above, via the metabolism process CBD can interact with other medications you are taking. All medications can interact with one another in this way.
The safety profile of CBD has been acknowledged by major health agencies such as the World Health Organisation, showing that it is well tolerated by animals and humans, and rarely produces any dangerous side effects. It also has a profound impact on an array of different systems in the body, explaining its therapeutic versatility.
However, this versatility is also the reason that CBD interacts with so many prescriptions and over-the-counter medications. So, even if CBD does interact with your medications, the chances of it causing extreme danger are slim. Although, you should still consult a medical professional before using CBD alongside any medications, as the risk is ever-present, and everybody is different.
We’ve researched the interaction of CBD with some common medications:
CBD and ibuprofen
This is a non-steroidal anti-inflammatory medication, meaning it can produce similar benefits to CBD in terms of inflammation and pain relief. There haven’t been any reported interactions between CBD and ibuprofen, but this isn’t to say that they won’t occur.
Potential interactions may be dosage dependent. If a certain threshold is breached, mixing the two could lead to severe nervous system pathology.
CBD and Lamictal
Whilst cannabis could increase side effects like dizziness, confusion and drowsiness, none of these side effects are proven to result from the usage of CBD. Depending on the dosage, CBD could simply make the medication more or less effective.
CBD and antibiotics
There is no known interaction with antibiotics, however, if the antibiotic in question is metabolised through the CYP450 system then there could be a small interaction. CBD and antibiotics could even amplify the effects of one another without any negative side effects in this circumstance.
CBD and omeprazole
CBD can inhibit the enzymes that are targeted by omeprazole and other proton pump inhibitors (PPIs). Taking CBD with certain heartburn medications can increase the risk of diarrhoea.
CBD and thyroid medications
Some people report mild nausea when taking CBD oil together with thyroid medications. Since both substances are processed by CYP450, taking CBD with a thyroid medication may cause hyperthyroidism, because more thyroxine would be secreted than the body could metabolise.
CBD and blood pressure medications
CBD can temporarily lower blood pressure, so taking it alongside specific blood pressure medication, such as lisinopril, might reduce it even more. This can result in making you feel lethargic and weak. Always consult your doctor before adding CBD to your routine if you use anti-hypertension medication.
CBD and antidepressants
Both CBD and antidepressants, such as SSRIs, can be used to combat depression. However, you should be cautious when using both at the same time. It can be difficult to combine antidepressants with CBD as CBD can change the way the medication is processed and inhibit its effects on the brain.
CBD and blood thinners
CBD may act as a blood thinner, which means it can help to reduce the formation of blood clots. When you take this together with an anticoagulant, it can contribute to additional blood thinning.
Why you should always consult your doctor
The list above is by no means extensive or definite, so it is intended to be used as a guide only. A consultation with your doctor will help you to establish the right routine for your medications and supplements, to avoid any potentially negative interactions. Some compounds work synergistically with CBD, so asking your doctor may even help you to maximise the effects of your treatment.